Gas Circuit Breaker

ABSTRACT

Realized is a shape of a grooved cam that maximizes break performance by appropriately setting an electrode operation, with a minimum weight increase. A gas circuit breaker includes a drive side electrode and a driven side electrode which are disposed to face each other in a sealed tank, the drive side electrode having a drive side main electrode and a drive side arcing contact, the driven side electrode having a driven side main electrode and a driven side arcing contact, the drive side arcing contact being connected to an operating device, and the driven side arcing contact being connected to a double motion mechanism portion, in which the double motion mechanism portion includes a drive side connection rod that receives driving force from the drive side electrode, a driven side connection rod that is connected to the driven side arcing contact, a lever that is bent to the operating device side around a rotation axis by causing the driven side connection rod to operate in an opposite direction with respect to an operation of the drive side connection rod, and a guide that defines operations of the drive side connection rod and the driven side connection rod.

TECHNICAL FIELD

The present invention relates to a gas circuit breaker to which a doublemotion mechanism that drives electrodes in directions opposite to eachother is applied.

BACKGROUND ART

In a gas circuit breaker which is used for an electrical power system ofa high voltage, a so-called puffer type that breaks an electricalcurrent by using an increase of an arc extinction gas pressure in themiddle of an opening pole operation and spraying a compressed gas to anarc generated between electrodes, is generally used.

In order to reduce operating force (cost) while maintaining breakperformance of the puffer type gas circuit breaker, a drive method inwhich a relative deviation speed between the electrodes facing eachother is made large, has been proposed.

In PTL 1, a drive method in which only an operation section necessary tobreak only an electrode is accelerated in a movable component connectedto a drive source, is proposed. This is a drive method in which a leveris moved together with a movable portion along a fixed grooved cam, andis rotationally moved along a grooved cam curved surface in theoperation necessary section, and the electrode is accelerated in thesame direction as a drive direction.

In PTL 2, a drive method (double motion method) in which a fixedelectrode (driven side) of the related art that is disposed to face amovable portion (drive side) connected to a drive source operates in anopposite direction to a drive direction, is proposed. This is a drivemethod in which a fork type lever of which a rotation axis is fixed ontoa pin working coupled with a movement of the movable portion isrotationally moved, and a counter electrode is accelerated in theopposite direction to the drive direction.

CITATION LIST Patent Literature

PTL 1: JP-A-2003-109480

PTL 2: U.S. Pat. No. 6,271,494

SUMMARY OF INVENTION Technical Problem

In the method of being moved in the same direction as the drivedirection described in PTL 1, since the grooved cam is used, it ispossible to appropriately set an electrode position at each time in theoperation section in accordance with the break performance, but weightis increased since there is a need to attach a drive mechanism ofelectrode acceleration to the movable portion, and it is not possible tomake the operating force of the drive source sufficiently small.

In the method described in PTL 2, since a drive mechanism is fixedindependently from the movable portion, it is possible to make theoperating force of the drive source sufficiently small by preventing aweight increase of the movable portion to be minimum, but it is notpossible to appropriately set the position of the driven side electrodeat each time since a shape of the fork type lever is configured onlywith a straight line portion and a circular arc portion.

Solution to Problem

In order to solve the problems described above, the invention provides agas circuit breaker including a drive side electrode and a driven sideelectrode which are disposed to face each other in a sealed tank, thedrive side electrode having a drive side main electrode and a drive sidearcing contact, the driven side electrode having a driven side mainelectrode and a driven side arcing contact, the drive side arcingcontact being connected to an operating device, and the driven sidearcing contact being connected to a double motion mechanism portion, inwhich the double motion mechanism portion includes a drive sideconnection rod that receives driving force from the drive sideelectrode, a driven side connection rod that is connected to the drivenside arcing contact, a lever that bends the driven side connection rodto the operating device side around a rotation axis by causing thedriven side connection rod to operate in an opposite direction withrespect to an operation of the drive side connection rod, and a guidethat defines operations of the drive side connection rod and the drivenside connection rod, and the lever is rotationally moved, the drivenside connection rod is driven in a direction which is opposite to thedrive side connection rod, and the driven side arcing contact that isconnected to the driven side connection rod is driven in a directionwhich is opposite to the drive side arcing contact of the drive sideelectrode that is connected to the drive side connection rod, by causinga movable pin to communicate with a grooved cam that is included in thedrive side connection rod and a pin communication portion that isdisposed in the guide, and moving the movable pin in the grooved cam dueto the operation of the drive side connection rod.

Advantageous Effects of Invention

According to the configuration described above, it is possible torealize a shape of a grooved cam that maximizes break performance byappropriately setting an electrode operation, with a minimum weightincrease, and a drive mechanism onto which the same is mounted.

It is possible to make displacement of an opening-closing axis directionlarge due to a rotation, by bending the lever to the operating deviceside around the rotation axis, and in a case where a stroke length ofthe driven side is the same as in the related art, it is possible tomake a width of a direction which is perpendicular to an opening-closingaxis small.

As described above, according to the invention, it is possible torealize the shape of the grooved cam to minimize energy of the operatingdevice while securing the break performance, and it is possible to makeoperation energy small in comparison with the drive method of therelated art. Since it is possible to relieve excessive force acting onthe movable pin, it is possible to realize a double motion mechanism ofhigh reliability.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a detailed diagram illustrating a state immediately before anoperation of a driven side electrode in the middle of opening pole of adouble motion mechanism in a gas circuit breaker according to Example 1.

FIG. 2 is a diagram illustrating a closing pole state of the gas circuitbreaker according to Example 1.

FIG. 3 is an exploded perspective view of the double motion mechanism inthe gas circuit breaker according to Example 1.

FIG. 4 is a diagram illustrating stroke properties of the gas circuitbreaker according to Example 1.

FIG. 5 is a diagram illustrating a state immediately before an operationof a driven side arcing contact, in the middle of opening pole of thegas circuit breaker according to Example 1.

FIG. 6 is a diagram illustrating an end state of the operation of thedriven side arcing contact, in the middle of opening pole of the gascircuit breaker according to Example 1.

FIG. 7 is a diagram illustrating an opening pole state of the gascircuit breaker according to Example 1.

FIG. 8 is a diagram illustrating a speed ratio of a drive side arcingcontact and the driven side arcing contact in the gas circuit breakeraccording to Example 1.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a gas circuit breaker according to an embodiment of theinvention will be described with reference to the drawings. Thefollowing description is merely an example, and does not have a purposefor intending to limit contents of the invention to specific aspectsdescribed below. It is possible to carry out the invention itself invarious aspects in conformity with the contents described in the scopeof the claims. In the following example, a breaker having a mechanicalcompression chamber and a thermal expansion chamber will be described bybeing used as an example, but for example, it is possible to apply theinvention of the present specification to the breaker having only themechanical compression chamber.

Example 1

FIG. 2 illustrates an input state of a gas circuit breaker in Example 1.

A drive side electrode and a driven side electrode are disposed tocoaxially face each other in a sealed tank 100. A drive side electrodehas a drive side main electrode 2 and a drive side arcing contact 4, andthe driven side electrode has a driven side main electrode 3 and adriven side arcing contact 5.

An operating device 1 is disposed by being adjacent to the sealed tank100. A shaft 6 is connected to the operating device 1, and the driveside arcing contact 4 is disposed at a tip of the shaft 6. The shaft 6and the drive side arcing contact 4 are disposed by passing through amechanical compression chamber 7 and a thermal expansion chamber 9.

The drive side main electrode 2 and a nozzle 8 are disposed on a breakportion side of the thermal expansion chamber 9. The driven side arcingcontact 5 is disposed on the same axis by facing the drive side arcingcontact 4. One end of the driven side arcing contact 5, and a tipportion of the nozzle 8 are connected to a double motion mechanismportion 10.

As illustrated in FIG. 2, the gas circuit breaker is set at a positionwhere the drive side main electrode 2 and the driven side main electrode3 are made to be conductive by a drive source due to an oil pressure ora spring of the operating device 1 in the input state, and configures acircuit of an electric power system of normal time.

When a short circuit current due to lightning or the like is broken, theoperating device 1 is driven in an opening pole direction, and the driveside main electrode 2 and the driven side main electrode 3 are separatedthrough the shaft 6. At that time, an arc is generated between the driveside arcing contact 4 and the driven side arcing contact 5. The arc isextinguished by spraying a mechanical arc extinction gas with themechanical compression chamber 7, and spraying an arc extinction gas byusing arc heat with the thermal expansion chamber 9, thereby, anelectrical current is broken.

In order to reduce operation energy of such a puffer type gas circuitbreaker, a double motion mechanism portion 10 that drives the drivenside arcing contact which is fixed as before in an opposite direction toa drive direction of the drive side electrode, is disposed. Hereinafter,a double motion method in Example 1 will be described, based on FIG. 1,FIG. 3, and FIG. 4.

As illustrated in FIG. 1 and FIG. 3, the double motion mechanism portion10 of Example is configured by connecting a driven side connection rod13 and a drive side connection rod 11 to a lever 12 which is disposed tobe freely rotationally moved in a guide 14, while retaining the drivenside connection rod 13 and the drive side connection rod 11 to be freelymoved in a break operation direction by the guide 14.

A grooved cam 16 is cut into the drive side connection rod 11, and isconfigured with a second straight line portion 16C, a connecting portion16B, and a first straight line portion 16A, when viewed from anoperating device side. The first straight line portion 16A and thesecond straight line portion 16C are disposed on axis lines which aredifferent from each other, and the connecting portion 16B is disposedtherebetween. It is possible to arbitrarily design a shape of theconnecting portion 16B in accordance with operation properties of thebreak portion, and for example, it is conceivable to make a curve or astraight line.

In the drive side connection rod 11, displacement of up and downdirections is limited by a groove which is disposed in the guide 14 (seegroove 14A and groove 14B in FIG. 3), and the movement is possible onlyin a direction which is horizontal to an operation axis of the breakportion.

A drive side movable pin 17 communicates with a circular hole 26 and thegrooved cam 16 which are cut into the lever 12. At this time, a guidenotch portion 14C is disposed, thereby, interference between the driveside movable pin 17 and the guide 14 is prevented. The guide notchportion 14C may be a communicating hole that covers a movable range ofthe drive side movable pin 17. By making the communicating hole, it ispossible to enhance mechanical strength of the guide 14. The lever 12has a circular hole 27, and a driven side movable pin 18 communicateswith the lever 12 and the driven side connection rod 13. The drive sidemovable pin 17 fastens a drive side movable pin fastening screw 24 witha drive side movable pin fixing nut 25 by using a drive side movable pinhexagon head 23.

The drive side movable pin 17 is moved in the grooved cam 16 of thedrive side connection rod 11, thereby, the lever 12 rotates by using alever fixing pin 15 as a rotation axis. By the rotational movement, alever driven side guide groove 19 which is cut into the lever 12transmits force to the driven side movable pin 18 which is attached tothe driven side connection rod 13, thereby, the driven side connectionrod 13 which is connected to the driven side arcing contact 5 is drivenin a direction which is opposite to the drive side connection rod 11.

For example, the connection of the double motion mechanism portion 10and the drive side has a structure in which a fastening ring 20 isattached to the nozzle 8, a hole passing through the tip portion of thedrive side connection rod 11 is disposed in the fastening ring 20, and adrive side fastening screw 21 is fastened with the nut.

The lever fixing pin 15 may be configured by one member to pass throughthe guide 14 and the lever 12, but as illustrated in FIG. 3, it isdesirable to make a configuration in which the lever fixing pin 15 isdisposed as two members respectively at both ends of the guide 14, andthe lever 12 is retained to be freely rotationally moved from bothsides. In order not to detach the lever fixing pin 15 from the guide 14,for example, a lever fixing pin snap ring 22 is fit into the grooveswhich are respectively cut into at both ends of the pin, thereby, therealization thereof is possible. By making such a configuration, it ispossible to design the lever fixing pin 15 without concern of theinterference with the drive side connection rod 11, thereby, degrees offreedom in design are enhanced.

The lever 12 is bent to the operating device side at an angle θa whichis 90 degrees or more and less than 180 degrees. The angle θa is setsuch that a ratio L1/L2 of a driven side arm length L1 and a drive sidearm length L2 is made as small as possible for the purpose of enhancingtransmission efficiency of the force, and an interval D between thedrive side connection rod and the driven side connection rod is made assmall as possible in order to be tightly fit into the breaker. An angleθb of the straight line obtained by binding a Y-axis, the lever fixingpin 15, and the driven side movable pin 18 is desirable to be set suchthat the driven side arm length L1 is made as small as possible, and theangle is equal with respect to the Y-axis at the time of starting andending the rotational movement of the lever.

In a state immediately before the operation of the driven side arcingcontact 5 illustrated in FIG. 1, the arm length of the drive side ispositioned on the operating device 1 side with respect to the Y-axis(θc_1>0), and in an end state of the operation of the driven side arcingcontact 5 illustrated in FIG. 6, the arm length of the drive side ispositioned on the drive side connection rod 11 side with respect to anX-axis (θc_2>0). This is because rotating force of one direction isapplied to the lever 12 at all times by the force which is received froma surface of the grooved cam 16 when the drive side movable pin 17 movesthe connecting portion 16B of the grooved cam 16.

In order not to apply the force in a direction which is perpendicular tothe opening pole direction, it is desirable that the lever 12 is made ina bilaterally symmetrical shape. Therefore, in Example, a structure ofcutting out a lower portion of the lever to sandwich the drive sideconnection rod 11, is made.

Hereinafter, the description will be made per state in the middle of theopening pole operation, by using FIG. 4 to FIG. 7.

FIG. 4 is a diagram in which a horizontal axis indicates time, and avertical axis indicates a drive side electrode stroke and a driven sideelectrode stroke. Time a is time of an opening pole start, and time b istime immediately before the operation of the driven side arcing contact5 (state of FIG. 5). Time c is time of an operation end of the drivenside arcing contact 5 (state of FIG. 6). Time d is time at which thedrive side operation is completed, and the state reaches to an openingpole state (state of FIG. 7). The stroke of both electrodes at eachtime, for example, the stroke from the time a to the time b of the driveside arcing contact 4 is represented by s4ab.

FIG. 5 is a diagram illustrating a state immediately before theoperation of the driven side arcing contact 5. In the stroke from time ato time b, the drive side arcing contact 4 is s4ab (≠0), the driven sidearcing contact 5 is s5ab (≠0), and the driven side arcing contact 5 isstopped. That is, the state where the driven side arcing contact 5 isstopped while the straight line portion of the second straight lineportion 16C of the grooved cam passes through the drive side movable pin17, is realized (the state is referred to as an intermittent drive,hereinafter). In other words, by adjusting the length of the secondstraight line portion 16C, it is possible to move the driven side onlyin an arbitrary time domain.

FIG. 6 is a diagram illustrating an end state of the operation of thedriven side arcing contact 5. In the stroke from time a to time c, thedrive side arcing contact 4 is s4ac (>s4ab), the driven side arcingcontact 5 is s5ac (>s5ab), and both electrodes are moved. At this time,the drive side movable pin 17 approaches the first straight line portion16A of the grooved cam.

FIG. 7 is a diagram illustrating the opening pole state. In the strokefrom time a to time d, the drive side arcing contact 4 is s4ad (>s4ac),the driven side arcing contact 5 is s5ad (=s5ac), and the driven sidearcing contact 5 is stopped. The intermittent drive state where thedriven side arcing contact 5 is stopped while the first straight lineportion 16A of the grooved cam passes through the drive side movable pin17, is realized.

As described above, the drive side movable pin 17 is moved in thegrooved cam by the connecting portion 16B of the grooved cam, thereby,the driven side arcing contact 5 is driven in the opposite direction tothe opening pole direction by rotationally moving the lever 12, and theoperation of the drive side movable pin 17 is limited by the firststraight line portion 16A and the second straight line portion 16C ofthe grooved cam 16, thereby, the intermittent drive state where thedriven side arcing contact 5 is stopped, is made.

As Example, the bending angle θa of the lever 12 is set to be equal to adeflection angle of the lever 12 with respect to an opening-closingoperation axis which is perpendicular to an opening-closing axis,thereby, it is possible to realize the space-saving double motionmechanism.

FIG. 8 is a diagram in which the horizontal axis indicates the stroke ofthe drive side arcing contact 4, and the vertical axis indicates a speedratio of the driven side arcing contact 5 to the drive side arcingcontact 4. In Example, when the drive side arcing contact 4 reaches thestroke s4ab, the driven side arcing contact 5 starts to move, and thedriven side arcing contact 5 stops at s4ac. A rise is made suddenacceleration, and deceleration is made at two-step. This is because adistance between the electrodes is made long in a short time, by sharplyaccelerating the driven side arcing contact 5 from time b (see FIG. 4)at which the driven side arcing contact 5 cuts through the drive sidearcing contact 4.

Such an operation is particularly effective for the break of the smallprogress electrical current. In the break of the small progresselectrical current, there is a need that a dielectric breakdown voltagebetween the electrodes at each time of the break surpasses a recoveryvoltage. This is because there is a need to earn the distance betweenthe electrodes as much as possible in a short time since the dielectricbreakdown voltage between the electrodes depends on the distance betweenthe electrodes at each time.

In Example, the shape of the grooved cam of the double motion mechanismthat can realize stroke properties which are necessary to break thesmall progress electrical current is illustrated, but there are the mostsuitable stroke properties with respect to various break duties, and itis possible to realize the stroke properties by changing the shape ofthe connecting portion 16B which is configured with an arbitrary curveof Example.

REFERENCE SIGNS LIST

-   -   1: OPERATING DEVICE    -   2: DRIVE SIDE MAIN ELECTRODE    -   3: DRIVEN SIDE MAIN ELECTRODE    -   4: DRIVE SIDE ARCING CONTACT    -   5: DRIVEN SIDE ARCING CONTACT    -   6: SHAFT    -   7: MECHANICAL COMPRESSION CHAMBER    -   8: NOZZLE    -   9: THERMAL EXPANSION CHAMBER    -   10: DOUBLE MOTION MECHANISM PORTION    -   11: DRIVE SIDE CONNECTION ROD    -   12: LEVER    -   13: DRIVEN SIDE CONNECTION ROD    -   14: GUIDE    -   14C: GUIDE NOTCH PORTION    -   15: LEVER FIXING PIN    -   16: GROOVED CAM    -   16A: FIRST STRAIGHT LINE PORTION    -   16B: CONNECTING PORTION    -   16C: SECOND STRAIGHT LINE PORTION    -   17: DRIVE SIDE MOVABLE PIN    -   18: DRIVEN SIDE MOVABLE PIN    -   19: LEVER DRIVEN SIDE GUIDE GROOVE    -   20: FASTENING RING    -   21: DRIVE SIDE FASTENING SCREW    -   22: LEVER FIXING PIN SNAP RING    -   23: DRIVE SIDE MOVABLE PIN HEXAGON HEAD    -   24: DRIVE SIDE MOVABLE PIN FASTENING SCREW    -   25: DRIVE SIDE MOVABLE PIN FIXING NUT    -   26: CIRCULAR HOLE    -   27: CIRCULAR HOLE    -   100: SEALED TANK    -   L1: DRIVEN SIDE ARM LENGTH    -   L2: DRIVE SIDE ARM LENGTH

1. A gas circuit breaker comprising: a drive side electrode and a drivenside electrode which are disposed to face each other in a sealed tank,the drive side electrode having a drive side main electrode and a driveside arcing contact, the driven side electrode having a driven side mainelectrode and a driven side arcing contact, the drive side arcingcontact being connected to an operating device, and the driven sidearcing contact being connected to a double motion mechanism portion,wherein the double motion mechanism portion includes a drive sideconnection rod that receives driving force from the drive sideelectrode, a driven side connection rod that is connected to the drivenside arcing contact, a lever that is bent to the operating device sidearound a rotation axis by causing the driven side connection rod tooperate in an opposite direction with respect to an operation of thedrive side connection rod, and a guide that defines operations of thedrive side connection rod and the driven side connection rod, and thelever is rotationally moved, the driven side connection rod is driven ina direction which is opposite to the drive side connection rod, and thedriven side arcing contact that is connected to the driven sideconnection rod is driven in a direction which is opposite to the driveside arcing contact of the drive side electrode that is connected to thedrive side connection rod, by causing a movable pin to communicate witha grooved cam that is included in the drive side connection rod and apin communication portion that is disposed in the guide, and moving themovable pin in the grooved cam due to the operation of the drive sideconnection rod.
 2. The gas circuit breaker according to claim 1, whereinthe grooved cam is configured with a first straight line portion, asecond straight line portion that is disposed on an axis which isdifferent from the first straight line portion, and a connecting portionthat connects the first straight line portion and the second straightline portion to each other.
 3. The gas circuit breaker according toclaim 1, wherein the lever is supported to be freely rotationally movedby lever fixing pins which are respectively disposed on both sides ofthe guide.
 4. The gas circuit breaker according to claim 2, wherein thelever is supported to be freely rotationally moved by lever fixing pinswhich are respectively disposed on both sides of the guide.
 5. The gascircuit breaker according to claim 1, wherein an operation angle whichis formed by the lever from a start to an end of an opening-closingoperation, is substantially the same as an angle with respect to a linethat is perpendicular to an opening-closing operation axis passingthrough a central point of the lever fixing pin.
 6. The gas circuitbreaker according to claim 2, wherein an operation angle which is formedby the lever from a start to an end of an opening-closing operation, issubstantially the same as an angle with respect to a line that isperpendicular to an opening-closing operation axis passing through acentral point of the lever fixing pin.
 7. The gas circuit breakeraccording to claim 3, wherein an operation angle which is formed by thelever from a start to an end of an opening-closing operation, issubstantially the same as an angle with respect to a line that isperpendicular to an opening-closing operation axis passing through acentral point of the lever fixing pin.
 8. The gas circuit breakeraccording to claim 4, wherein an operation angle which is formed by thelever from a start to an end of an opening-closing operation, issubstantially the same as an angle with respect to a line that isperpendicular to an opening-closing operation axis passing through acentral point of the lever fixing pin.
 9. The gas circuit breakeraccording to claim 1, wherein a central point of the movable pin ispositioned on the operating device side with respect to the line that isperpendicular to the opening-closing operation axis passing through thecentral point of the lever fixing pin.
 10. The gas circuit breakeraccording to claim 2, wherein a central point of the movable pin ispositioned on the operating device side with respect to the line that isperpendicular to the opening-closing operation axis passing through thecentral point of the lever fixing pin.
 11. The gas circuit breakeraccording to claim 1, wherein the central point of the movable pin ispositioned on a lower side with respect to the opening-closing operationaxis passing through the central point of the lever fixing pin.
 12. Thegas circuit breaker according to claim 2, wherein the central point ofthe movable pin is positioned on a lower side with respect to theopening-closing operation axis passing through the central point of thelever fixing pin.
 13. The gas circuit breaker according to claim 1,wherein when the movable pin is moved in the first straight line portionand the second straight line portion, the lever is stopped, and when themovable pin is moved in the connecting portion, the lever rotates arounda supporting point.
 14. The gas circuit breaker according to claim 2,wherein when the movable pin is moved in the first straight line portionand the second straight line portion, the lever is stopped, and when themovable pin is moved in the connecting portion, the lever rotates arounda supporting point.
 15. The gas circuit breaker according to claim 1,wherein in an opening pole operation, the movable pin is moved on thesecond straight line portion, the connecting portion, and the firststraight line portion in one direction, and in a closing pole operation,the movable pin is moved on the first straight line portion, theconnecting portion, and the second straight line portion in onedirection.
 16. The gas circuit breaker according to claim 2, wherein inan opening pole operation, the movable pin is moved on the secondstraight line portion, the connecting portion, and the first straightline portion in one direction, and in a closing pole operation, themovable pin is moved on the first straight line portion, the connectingportion, and the second straight line portion in one direction.
 17. Thegas circuit breaker according to claim 1, wherein a positionalrelationship of the first straight line portion, the second straightline portion, and the connecting portion of the grooved cam isdetermined by a speed ratio of a driven side operation to a drive sideoperation.
 18. The gas circuit breaker according to claim 2, wherein apositional relationship of the first straight line portion, the secondstraight line portion, and the connecting portion of the grooved cam isdetermined by a speed ratio of a driven side operation to a drive sideoperation.